Firstly I have Error(8180) In MB_MASTER But When I true the REQ BIT Of MB_COMM_LOAD ,Error get FALSE.

& Where Should i check the Data of Energy meter

Hello Vicky Bjau;

From reading your questions in this thread, I cannot say what level of experience you have on Modbus exchanges, especially with a Siemens PLC as master. May I suggest you take a few minutes to read an excellent primer prepared by one of our experts on the subject, our friend smiffy. For beginners it is very helpful, for more experienced users it is a great refresher on Modbus:

https://support.industry.siemens.com/tf/ww/en/posts/modbus-general-description/66876/?page=0&pageSize=10

Then, correct the error 8180 that you show on your Modbus functions, so that when they are right you can use them to connect to your Energy Meter and request data.

https://support.industry.siemens.com/tf/ww/en/posts/mb-master-and-error-8180/55893/?page=0&pageSize=10

https://support.industry.siemens.com/tf/ww/en/posts/error-mb-master/94257/?page=0&pageSize=10

Next, study this Schneider document showing Modbus functions and the register addresses where data of your Energy Meter can be located on the Modbus  slave:

https://support.industry.siemens.com/tf/ww/en/posts/error-mb-master/94257/?page=0&pageSize=10

As suggested earlier, begin by using a Modbus master program on your PC, as a communication test. Schneider seems to suggest (on page 54) that Modscan and Modtest are suitable for these initial data exchanges. Once the Modbus communications are validated with a test program, for example by reading the first current value, Current Average at address 3913 (start Modbus address of the Holding registers + offset 12), then you can build up your own Modbus exchanges with the PLC as Modbus master.

If you have any more specific questions about your programming, please feel free to ask; make sure you provide enough information for us to be able to help.

Hope this helps,

Daniel Chartier

sir,

   Do You Have any backup where there is communication with third party on modbus rs485,& also there is my backup please confirm that the instruction used are correct,i have used MB_COMM_LOAD & MB_MASTER